1. Field of the Invention
The present invention is related generally to a data processing system and in particular to a method and apparatus for checkpoint operations. More particularly, the present invention is directed to a computer implemented method, apparatus, and computer usable program code for checkpointing and restoring UNIX® domain sockets in a workload partition environment.
2. Description of the Related Art
Data processing systems frequently utilize data integrity operations to ensure that the state of data stored in memory may be recreated in the event of a failure. A checkpoint operation is a data integrity operation in which the application state and memory contents for an application running on the kernel are written to stable storage at particular time points to provide a basis upon which to recreate the state of an application in the event of a failure. The particular time point at which state and memory contents are written to stable storage may be referred to as a checkpoint.
During a checkpoint operation, an application's state and data may be saved onto a local disk or a network disk at various pre-defined points in time to generate checkpoint data. When a failure occurs in the data processing system, a restart operation may be performed using the checkpoint data to roll back the state of the application to the last checkpoint. In other words, the application data may be restored from the checkpoint values stored on the disk.
AIX® workload partition (WPAR) is a product available from International Business Machines (IBM®) Corporation. A workload partition is a portion or representation of an operating system within a virtualized operating system environment. In a workload partition environment, an operating system image within a kernel can be partitioned into multiple virtual operating system instances. Each virtual operating system instance is a separate workload partition within the kernel.
Software running within each workload partition will appear to have its own separate instance of the operating system. A workload partition may include one or more processes. The processes in one partition are not allowed to interact with processes in other workload partitions.